Pipe damper



H. KNUTSON Get. 20, 1931.

PIPE DAMPER Filed Nov. 4, 1929 v HAROLD KNUTSON, or CHICAGO,

Patented Oct. 20, 1931 umrao sums PATENT came,

roiea'rnn; a conronarron or ILLINOIS PIPE DAMPER I Application filed November 4, 1929.. Serial No. 404,632.

The invention relates to new and improved means for controlling the passageway through pipes, as for example, the vertical pipes of chimneys and analogous dra ft de- I vices, and is particularly applicable to means for positively controlling currents of air or other gases through ventilator pipes.

; from the followingdescription,

It is the primary object of the invention to provide a closure means or damper for the interior of a pipe, as for example, the exhaust pipe of a ventilator, which means shall be under convenient control of an operator from the exterior of the pipe. 7

Other objects of the invention will appear which is directed to the preferred embodiment of my invention, the samebeing shown in connectionwith thevertical exhaust pipe ofa ventilator of the type adapted to convey air, smoke or other, gases through the roofs or wallsof buildings, as hereinafter described and shown in the accompanying drawings forming a part of the specification, the novel features being set forth in the appended claims. In the said drawings: p l Fig. 1 is a conventional form of ventilator adapted to project through the roof of the building with the inlet end of the ventilator pipe extending below theroof and in position to receive air, smoke or other lighter than air materials, and to convey the same from the interior to the exterior of the building, the

device being shown installed in the pipe of the ventilator orchimney. I

Fig. 2 is an enlargedsectional' view of a vertical pipe showing the invention installed therein, the damper being in the closed position.

the invention may be applied to pipes orducts of any desired shape.

In the embodiment of the invention shown,

I the pipe is a vertical ventilator pipe or chimney,

Fig. 3 is a view similar to Fig. 2"showinginstalled through the: apex of a roof structure designated by reference character 11. Such pipes, when utilized for ventilation pur; poses, are now commonly supplied .with terminal portions adapted to be, positioned on the exterior of buildings so that powerful updraftsmay be created through such pipes byvacuum produced at the top of the pipe, due to air currents moving horizontally over the top of the-pipe. shown and described in my U. S. Patent No.

1,728,494 granted September 1-7, 1929, :and it is to ventilator pipes of the character shown in mysaid patent that my invention is particularly applicable, as 111 provides'a readily controllable means-for shutting off the operation of. the ventilator and for controlling it" in various ,degreesof intermediate adjustment, 'thus enabling the attendant from a convenient position on the ground near a building, oron the floor of the interior of a building to control therate of air currents passing through such automatically'operated devices, especially in cool or winter weather when continued lateral air currents of extreme velocity strike such ventilators.- It has heretofore been difficult to prevent thetoo rapid exhaustion ofthe air on the interior of-the building, to which such ventilatorsare attached. j v V o I In the form of ventilator pipe shown in Fig. 1, however, the top thereof is merely illustrated as equipped with a conventional form of cowl or cap 12 supported by short up rights-13 attached to the cowl and to the upper end of the pipe and supported by the latter a sufiicient distance abovethetop of the ventilator pipe-1O to permit a free exhaustion of moving currents into and out of commonly circular in cross section, but it will be obvious that the invention will be applicable to pipes and their dampers of any deosired shape. The damper 15 is pivotally con- Such a ventilator top is ILLINOIS, ssreivonro PAUL mo INsom Ncon for illustrative purposes shown 'as the latch bolt 20 is nected at 16on the interior of the pipe and the detail of such pivotal mounting in the pipe is not elaborated upon in the drawings, since this forms no part of the invention, and it willbe sufficient to state that the pivot 16 maybe inthe form of a continuous shaft'extending diametrically across thedamper mounted in suitable bearings, not shown, in r the wallsof the pipe 10 the connection of the shaft 16 to the damper being secured by any suitable means, as for example, by a pair of spaced brackets,designated by reference character 17, riveted to or otherwise suitably secured to the damper-'15. 18 is astop plate located on one side of the'pipe 10 opposite the pivotaliinounting of the damper,while on'the opposite side and substantially diametrically opposed to the stop 18, is yaj-fixed pro ectmg block 19 forming aproject-ing'ledgeor keeper for"co operating with'a spring pressed detent or latch '20, which is normally held in protracted position with the forward end thereof projecting-out of the casing 21'and beyond the'peripher of'the damper body 15. The ekposed-up'per surface of the keeper orblock 1 9 isbevelled and the lower surface thereof is atright angles to the'adjacentsurfac'e of the pipeso that a stop surface is provided 'beneathwhich the spring protracted latch will engage when the damper is in closed pos tion, the lateh 20 being projected to its normal engaging position by means ofacoil spring 22, interposed between theinner end of the 'c'asing'21 and a suitable crosspinor collar 23 on the latch 20. This latchor spring bolt 20 atitsinne'r end projectsbeyond the casing 21 and isthe're provided with: an eye 2l-tl1rough 1which' i'spassed a'flexible rope or cable '25. When lthedamper is to be used in a pipe or flue through which air or gasheated'to relathe flexible cable 25 should be of wire or other construetion' so as to i be non-inflammable.

*(Dn thesidefof thedamper 15 upon which positioned I mount "a bracket 26, supporting an anti-friction grooved sheave 27. Overthesheave 27* the cable 25 'is threaded and one end ofthis' cable is allowedto depend from the sheave 27-down through the-pipe 10 to some suitablecontrol point convenient for the operator or attendfant, such endf'o'f the cable being designated reference character 25a. The other end of the cable is "threaded over a grooved antiifrictionsheave 28 suitably supported in a ibr-ack'et29secured'to the inner wall of the pipe l0tandthis' free end of the cable 25, as

'aamper 1,5" and its spring indicated-M256, is also'preferably extended to the slame-p'ointof control asgthe end25ct thereof. Th'ecable 25 thus secured to the pressed latch member 20 afford "a convenient means whereby anteperator will be afforded complete remote c dnt'r'ol as-at a point at the bottom of'a buildes V v may be secured by The operation of the device will 'be as follows:

If the damper 15 be constructed of imperforate material and to substantially correspond when closed to the interior diameter of the pipe, it will obviously serve to substantially cut' oil drafts through the pipe when in theposition illustrated in Fig. 2, while in the open position, with theplanethereof sub stantially parallel-with the axial line'of the pipe, as illustrated in Figs. 1 and 8, the pipe will be substantially open or unobstructed with respect to the passage of currents of air therethrougln With the damper in the inoperative position, I find that it is an advan tage to provi de a counterweight 30- thereu p on, which will tend to hold it int'he vertical position without any particular controlling effect beingexerted thereupon by the cable25. The counter-weight will obviously be'suffi- 'cient to overcome the weight ofthe latch and cord on the opposite side of the'axial mounting of the damper, and this preponderance of weight may be increased according'lyas it maybe desired to cause the-damper to be operated to the open position by gravity in conjunction with the controlling action that theoperator through the fiexiblemember 25. 1

'VVhenthe damper is in 'the closed-position, extending transversely from side toside of the pipe 10, illustrated in Fig. 2, the upper edge of the damper opposite "the latch will contact with the sto p 18 which will serve as a'convenientmeans for preventing the overrunning'ofthe damper 115 when-thedamper is closedand the 'spring pressed latch 20 is causedto pass beneath thestop or catch 19. Afterthe damper 18 is brought to the closed position so that the latch20 passesbeneath itskeeper or stop 19, the'stop 18 will immediately become effective and it will be seen that with the damper in the closed position the operator from a ground orfloor position at a distance from the ventilatormay by a'pull upontheend 25b of'thecord or flexible'member 25 'cause'the springpressed latch 20to'be retracted against thej'normal pressure'of "the coil spring22. This will free the latch20 from beneaththe stop orkeeper 19 so'thatthe operator'then by retaining sufficientte'nsion uponthe flexible member to prevent'thereturno-f the latch, may, bypulling upon the free'en d 25a of the flexible member cause-the damper as ltap-pears inthe drawings to be rotated in a counter-clockwise di.rection,'due to the excess'pullupon the'sheave 2'7,causing the damper to assume the positions shown in Figs. 1 and 3 or any-other degree ofa'djustment in: the rotation thereof 'betwen the position "shown in the :last said figures and With the damperinthe open-position of pressed in a rotationof the damper in a clockwise direction as thedevice appears in the drawings, such pull overcoming the influence of the counter-weight 30 and causing the damper to be brought to any desired position of adjustment or to be quickly thrown to the position illustrated in Fig. 2 where the spring latch 20 will first contact with the bevelled upper edge of the stop or catch 19 which will cause the latch 20 to first enter its housing and then upon passing below the stop or vcatch 19 to engage the underside,

thereof, effectively locking the damper in the closed position.

I also show in the drawings a supplemental damper controlling segment that may conveniently be attached to the inside of the pipe 10 adjacent to and forming, in effect, a con-.

tinuation of the body of the stop or catch 19. This segment is designated generally by the reference character 35 and it comprises a metallic strip attached to the inner wall of the pipe at thevpoint of attachment of the catch. or stop 19. For illustrative purposes, it is shown attached with the catch or stop 19 by the samesecuring rivets or bolts and both the segment 35 and the. catch or stop 19 may be formed integrally, if desired. The curved bodyportion of the segment 35 follows the arc of a circle of which the pivot pin 16 of the damper is the center and the segment is provided with a plurality of spaced openings, there being three of such shown .in the drawings and designated by reference character 37. The length of the curved segmental portion 35 may be varied to suit the conditions of openings of the damper greater than the closed positionthereof indicated in Figs. 2 and 4, and less than the normal open positions thereof shown in Figs. 1 and 8, and these openings 37 will permit the operator to open the damper from the normally closed position to a point where the spring pressed latch 20 will engage either of the spaced holes 37 in the segment, thus locking the damper in intermediate positions,

as provided by the spacing of the holes 37, which will permit the damper to be efiective- 1v held in such intermediate positions, in

which positions the latch may obviously be released by the operator in the same manner as the latch 20 isreleased from the'catch 19 when the damper is operated to the closed position. The segmentallocking guide 35 may be recurved at its upper extremity to substantially a horizontal'position, as indicated at 38 and may be given a sharp angular bend adjacent the wall of the pipe .10 and secnred thereto by a suitable bolt or rivet as indicated at39.

In orderthat the invention may beunderstood the details of the preferred embodiment have been illustrated'anddescribed in detail but it is not desired to beflimited to the specific details of construction since persons skilled in the art may resort to various modifications without departing from the-purpose and spirit of my invention.-

hat I-cla1m as my lnvention and desireto secure by Letters Patent is: 1. The combination with a ventilator or other passageway for air, smoke'or other" gases, of a damperpivotally connected with the interior of said passageway, a spring pressed latch carried by the damper and provided with an eye, and a flexible'member for operatingthe damper threaded-through said eye and through a pair of suitable guides spaced from said eye andr'espectively mounted one upon said damper and the other upon the wall of the passageway. Y

'2. The combination with a ventilator or other passageway for air, smoke or other gases, of a damper pivotally connected with the interior of. said passageway, a. spring pressed latch carriedbythe damper andpro vided with an eye, a guide carried by the damper on the side of the pivotal axis thereof remote from the spring pressed latch, a sec- 1 ond guide carried by the wall of the passageway and a flexible member for operating the damper threaded through said eye and through said guide. I

3. The combination with a, ventilator or other passageway for air, smoke or other gases, of a'damperpivotally connected with the interior ofsaid passageway, a spring pressed latch carried by the damper and provided with an eye, a catch for the latch onv the wall of the passageway, a guide carried by the damper on the side of the pivotal axis thereof remote from the latch, a second guide secured to the wall of the passageway, and a flexible member for operating the damper threaded through'the said eye on the latch with the ends thereof beyond the eye threaded through the said'guides and extended through the passageway to a point accessible to an operator.

Y 4;. The combination with a. ventilator or other passageway for air, smoke or other gases, of a damper pivotally connected to the interior of said passageway, a spring pressed latch carried by the damper and provided with an eye, a catch for the latch secured to the wall at the passageway, a stop for the damper on the wall of the passageway diametrically opposite thesaid catch for the latch, an anti -friction sheave carried by the damper on the side of the pivotal axis thereof opposite the spring pressed latch, a vsecond passagewayawhereby thedamper may be com trolled and operated :to its respective open and closed positions. a s V 5. The icombinationriwith :a' ventilator or other passageway "for air, smoke or other gases, of a damperpivotally connected with the interior of said passageway, a spring pressed latchicarriedby the damper, a guide carried 'by the damper on the side of the pivotal axis-thereof remote from-the spring pressed latch, {a flexible member-threaded through said guide and operativelyi con- :neeted with the latch, and asegmental lockingmemberproviding a curved'surface adjacent the path iofmovement of the spring pressed latch, there being apiurality of latch engagingabutments formed in-said segmental locking member for engagement by said to lock said.

spring fpressed latch whereby damper in its adjusted positions.

In testimony whereof I have signed my name to thisspeeification, on this 9th day of October, A. D. 1929. H-AROLDKNUTSON. 

